bug#37538: [PATCH] Add docstring for `tags-complete-tags-table-file'.

[Hong Xu]

On 9/28/19 1:11 AM, Eli Zaretskii wrote:
> > From: Hong Xu <hong@topbug.net>
> > Date: Sat, 28 Sep 2019 00:59:21 -0700
> >
> > * lisp/progmodes/etags.el (tags-complete-tags-table-file): Add docstring.
>
> Thanks.  A comment below.
>
> > -(defun tags-complete-tags-table-file (string predicate what) ; Doc string?
> > +(defun tags-complete-tags-table-file (string predicate what)
> > +  "Complete file names in the current tags table.
> > +The meaning of the arguments are the same as the function form of
> > +COLLECTION as explained in Info node `(elisp) Programmed
> > +Completion'."
>
> The first line of the doc string should mention the arguments.  And we
> should explain STRING and WHAT there, because those aren't passed to
> all-completions and try-completion.

Please see my update below. I'm writing in this concise form because `(elisp) 
Programmed Completion' has a lot of explanation and I don't think we should 
repeat them here.

diff --git a/lisp/progmodes/etags.el b/lisp/progmodes/etags.el
index a03516100087..2770baa7067c 100644
--- a/lisp/progmodes/etags.el
+++ b/lisp/progmodes/etags.el
@@ -1843,13 +1843,18 @@ tags-query-replace
    delimited)
   (fileloop-continue))
 
-(defun tags-complete-tags-table-file (string predicate what) ; Doc string?
+(defun tags-complete-tags-table-file (string predicate what)
+  "Complete STRING from file names in the current tags table.
+The meaning of the arguments are the same as the function form of
+COLLECTION as explained in Info node `(elisp) Programmed
+Completion', except that if WHAT does not equal t, it is treated
+as if it were nil."
   (save-excursion
     ;; If we need to ask for the tag table, allow that.
     (let ((enable-recursive-minibuffers t))
       (visit-tags-table-buffer))
     (if (eq what t)
-       (all-completions string (tags-table-files) predicate)
+        (all-completions string (tags-table-files) predicate)
       (try-completion string (tags-table-files) predicate))))
 
 ;;;###autoload
--
2.20.1